package com.hollysys.usersync.utils;

import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.BeanWrapperImpl;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import java.util.HashSet;
import java.util.Set;

/**
 * Bean属性拷贝
 *
 * @author Jeremy Yim
 * @date 2019-09-12
 * <p>
 * 不同于 {@link BeanUtils#copyProperties(Object, Object)}
 * 该方法拷贝时会忽略sourceBean中为null的属性
 */
public class SpringBeanUtil implements ApplicationContextAware {

    /**
     * 当前IOC
     */
    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext arg0) throws BeansException {
        applicationContext = arg0;
    }

    /**
     * 从当前IOC获取bean
     *
     * @param id beanId
     */
    public static Object getObject(String id) {
        Object object = null;
        object = applicationContext.getBean(id);
        return object;
    }

    /**
     * 拷贝Bean不为null的属性
     *
     * @param src    源bean
     * @param target 目标bean
     */
    public static void copyPropertiesIgnoreNull(Object src, Object target) {
        BeanUtils.copyProperties(src, target, getNullPropertyNames(src));
    }

    //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

    private static String[] getNullPropertyNames(Object source) {
        final BeanWrapper src = new BeanWrapperImpl(source);
        java.beans.PropertyDescriptor[] pds = src.getPropertyDescriptors();

        Set<String> emptyNames = new HashSet<>();
        for (java.beans.PropertyDescriptor pd : pds) {
            Object srcValue = src.getPropertyValue(pd.getName());
            if (srcValue == null) {
                emptyNames.add(pd.getName());
            }
        }
        String[] result = new String[emptyNames.size()];
        return emptyNames.toArray(result);
    }

}
